<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Inner Transparent Shadows</title>
    <style>
        .box {
            width: 200px;
            height: 200px;
            background-color: #fff;
            box-shadow: 
                inset 0 0 0 5px rgba(0, 0, 0, 0.5); /* 四周阴影 */
        }
    </style>
</head>
<body>
    <div class="box"></div>
</body>
</html>